320153221 has 4 divisors (see below), whose sum is σ = 321551500. Its totient is φ = 318754944.

The previous prime is 320153209. The next prime is 320153263. The reversal of 320153221 is 122351023.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 122351023 = 17 ⋅7197119.

It can be written as a sum of positive squares in 2 ways, for example, as 301404321 + 18748900 = 17361^2 + 4330^2 .

It is a cyclic number.

It is not a de Polignac number, because 320153221 - 2¹¹ = 320151173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (320153201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 698796 + ... + 699253.

It is an arithmetic number, because the mean of its divisors is an integer number (80387875).

Almost surely, 2^320153221 is an apocalyptic number.

It is an amenable number.

320153221 is a deficient number, since it is larger than the sum of its proper divisors (1398279).

320153221 is a wasteful number, since it uses less digits than its factorization.

320153221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1398278.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 320153221 is about 17892.8259646150. The cubic root of 320153221 is about 684.0995296783.

The spelling of 320153221 in words is "three hundred twenty million, one hundred fifty-three thousand, two hundred twenty-one".